The present invention relates to the deflection of radiated energy and more particularly to an electro-optical light deflection apparatus.
A deflector of this kind may be of the digital type, i.e., it may be capable of deflecting a beam of incident radiated energy into one of a certain finite number of predetermined directions or it may be of the analog type, i.e., it may be capable of deflecting the incident beam in a direction which depends on the magnitude of an applied electrical signal. As an example, the active element in such a deflector may be made of a so-called electro-optical material, i.e., a material whose index of refraction can be changed by the action of an electric field; by shaping this material in an appropriate way, the direction of the emerging ray may be made a function of the applied electric field.
Also belonging in this class are so-called electro-acoustical deflectors, customarily consisting of a solid or liquid substance in which plane ultrasonic waves are created by means of an electrical potential and these waves cause diffraction of an incident luminous beam into a specified direction which is a function, particularly, of the applied electric potential.
In general, this type of deflector has the inherent inconvenience of permitting only a small angular deviation.